Home Metabolic myopathy: McArdle's disease

Metabolic myopathy: McArdle's disease

Types

Defining Characteristics

Exercise intolerance w/ premature fatigue in anaerobic ex, stiffness/weakness in exercising muscles relieved by rest; rhabdomyolysis w/ intense ex, second wind phenomenon

Disease Development

Myophosphorylase deficiency, preventing the breakdown of glycogen to glucose (glycogen cannot be converted to G6P)

Potential Causes

Defect in glycogen breakdown

Lab/Imaging

Histology? Abnormal deposits of glycogen